桜塚 名月

She is the older sister of Tsukumo and a school nurse. She's quite popular among the students and teachers. A rumor says that one of her former schoolmate - a rich medical doctor - would try to go out with her. In reality, this rumor was created by Tsukumo for stopping the boys who try to going out with his sister.
She's also the subject of the sexual fantaisies of her little brother who had a secret crush on her since ever.
 
She's a big fan of astrology and science fiction, she reads a lot of novels and often watches documentaries on television. She is an inconsiderate fan of the physicist and professor Kagami, she owns and has read all his books. 
Her favorite theme and subject is the time travel. One of her favorite writers is - among overs - Isaac Asimov.

Her passion for astrology and science fiction came from a "friend" she had in high school and who disappeared at that time. She used to call him "Onii-chan".
Given the way she talks about this "friend", he probably had to more than a simple "friend", maybe he had to be her lover.

Natsuki rejects Tsukumo because she is in love with her "friend" who has disappeared and can not love Tsukumo other than brotherly love. When he goes out with Mimi, she starts to depress and drink a bit more than before. Then, she realizes her true feelings ...

Then, she falls seriously ill due to a poison that has been circulating in her blood since she has getting hurt by rescuing Tsukumo of dying in 1999. Her death then triggers a chain of events for Tsukumo, in order to save her.

The traits corresponding to the state of her virginity have a value that varies according to the temporal line and the parallel dimension born as a result of a minor or major temporal change./

This ******e has another alternative version (from when she were even younger, in the year of 1996).